I have no personal recommendation but I would look locally if I were you. I hear horror stories about companies in India/China/etc that say they will develop an app for you and either just take some money and never deliver or make a half-assed attempt at something just to keep your money coming in. Locally you can actually sit down with someone and talk to them rather than trying to use the phone/skype/texting to convey everything you want.

of course you need to have money for an app in the first place so if you are trying to get an app made for nothing or even a very small amount and have the company/person take a percentage, I have no idea who would do that.

Absolutely agree, it's important to choose a good developer. A good app development company won’t be cheap, but it’ll be well worth the cost. Here is a good article, read it - woxapp.com/en/ios-apps-development/

When it comes to mobile app development, it's important to choose only the best developer in order to avoid tens or hundreds of thousands of dollars wasted. Based on my personal experience, I recommend SteelKiwi - https://steelkiwi.com/contacts/